点尺蠖的生物学特性

点尺蠖(Naxa(Desmonaxa)angustaria Leech)是桂花的重要食叶害虫之一,在南平、武夷山市一带1年发生2代,以4龄、少数3龄幼虫在丝网内越冬,幼虫7龄,幼虫群居为害叶片,为害期长(从上/3～上/12),常造成枝梢枯死,老熟幼虫于丝网上化蛹,成虫白天活动、交配,且具趋光性,卵串珠状呈4行排列,它的天敌有蜘蛛及姬蜂,并能起抑制作用,防治上采用人工捕杀卵、幼虫及蛹,以2.5％溴氰菊酯5000倍,40％乐果乳油2000倍,80％敌敌畏乳油2000倍和90％的敌百虫结晶800倍等试验和林间使用,对各龄幼虫均有显著防治效果(90％以上)。

Studies on Bionomics of Naxa (Desmonaxa) Angustaria Leech

Naxa ( Desmonaxa ) angustaria Leech is an important pest to Osmanthus fragrans Lour. The moth completes two generations per year under the labora-torial conditions in Nanping, Fujian Province. The larvae infest leaves and always live together, resulting in the dried twigs and eventually affecting the growth and development of plants. There are seven Larval instars. The old lar-vae change itself into papae on the silk-net. The adults fly day and night and lay egges on the silk in four lines as the shape of pearl. Control methodes include men-killing and use of pesticides, such as diluted 2.5% desis ( 1 : 500, v/v ) , 80% dichlorvos emulsion ( 1 : 2000, v/v ) , 90% dip-; terex crysta ( 1 : 800, v/v ) and 40% rogor emulsion ( 1 : 2000, v/v), which are sprayed on 4-5 phase larvae respectively and proved to be very effective(death rate 90% ) by the laboratorial experiment.